Joseph "Big Joey" Massino, the head of the Bonanno crime family for 14 years, is seen in this undated file photo released by the U.S. Attorney's Office. Photo Credit: AP

Joseph Massino, the former boss of the Bonanno crime family who made history by turning into a government witness, is expected to appear in court next week in a bid to get out of prison in return for his cooperation against his old mob associates.

Brooklyn federal prosecutors filed papers Monday asking Judge Nicholas Garaufis to cut Massino's life sentence for murder and racketeering in return for what they said was his "extremely valuable" cooperation that in 2011 led to the conviction of Vincent Basciano, his acting boss.

Massino secretly taped Basciano while both were in Brooklyn's federal Metropolitan Detention Center, and prosecutors used the recordings at trial.

In total, Massino, of Howard Beach, gave information that helped in the prosecution of 24 reputed members of organized crime, including many high-ranking members of the Bonanno family, Assistant U.S. Attorney Taryn Merkl said in her court filing. Massino's appearance as a witness in the Basciano case was the first time an official mob boss in New York City ever testified as a cooperator, and prosecutors said he helped decimate his old crime family.

Massino, now 70 and with health problems, offered his services to the government within minutes of his federal conviction for racketeering murder in July 2004. The jury in his case found that Massino played a role in seven mob hits, including the triple slaying in May 1981 of three Bonanno captains, Dominick "Big Trin" Trinchera, Alphonse "Sonny Red" Indelicato and Philip "Phil Lucky" Giaccone during a war for control of the crime family. Massino later admitted being involved in 12 killings.

In the early days of his cooperation, Massino steered the FBI to a vacant lot in Queens where the missing bodies of Trinchera and Giaccone were found in the fall of 2004. Indelicato's body was found at the same location in 1981.

A hearing on the government's request to get Massino a shorter sentence is scheduled for Thursday. Prosecutors didn't ask Garaufis to give Massino a specific sentence, but in previous mob cases cooperating witnesses have been let out of prison with time served. It is unclear whether the families of any of Massino's murder victims will ask to be heard about his resentencing.